NYC-WTC_000197642

NYC 9/11 Public Portal Document

104 East 25th St., 10th Floor New York, New York 10010 www.atc-enviro.com 212.353.8280 Fax 212.353.8306 ASSOCIATES INC.

July 17, 2002

Mr. Bernard P. Orlan Director, Environmental Health and Safety New York City Board of Education 28-11 Queens Plaza North Long Island City, NY 11101

Re: Air Sampling for Metals Stuyvesant High School ATC Project No. 15-19125-0246

Dear Mr. Orlan:

ATC Associates, Inc. (ATC) is pleased to provide this letter report of air sampling for metals in airborne dust on June 26, 2002, at the referenced school. The New York City Board of Education (BOE) requested this sampling at the recommendation of H. A. Bader, a consultant retained by the parents association.

SCOPE OF WORK

ATC collected three (3) samples for metals at specified locations. Samples were collected for a minimum of seven (7) hours using 37 mm mixed cellulose ester filter connected to battery- powered sampling pumps at a flow rate of 2 liters per minute. Pumps were calibrated before and after each sampling period. Two (2) samples were collected inside the building and one (1) was collected on the roof. Two blank samples were also submitted. The samples were sent to PSC Analytical Services, Inc., an American Industrial Hygiene Association-accredited laboratory in Reading, PA. Analysis was performed by NIOSH Methods 7300M. Each sample was analyzed for a panel of eleven (11) metals. The metals were aluminum (Al), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni) and zinc (Zn). A copy of the analytical report is attached.

The sampling locations were: the 1’* floor lobby, 2"** floor bndge entrance lobby and the Roof.

Tenzin Namgyal and Wagdi Abdelshahid conducted the sampling consistent with accepted industrial hygiene practices. The results represent conditions on the day the samples were collected.

The established regulatory values for metals in air are intended for industrial workplace exposures and are not generally applicable to office/school settings. There are no standards for metals in indoor air in non-industrial situations.

SAMPLE RESULTS

The only metal present at concentrations greater than the limits of detection was chromium. Cr was also detected in the field blank. Blank-corrected the Cr concentration lowers the concentrations to below or just above the limit of detection.

CITY_21MC100_003046798

NYC-WTC_000197642